Systems and methods for providing electrical stimulation of multiple dorsal root ganglia with a single lead

ABSTRACT

A method for implanting an electrical stimulation lead into a patient includes advancing a distal end of a multi-armed lead into an epidural space of the patient. The multi-armed lead includes first and second stimulation arms extending from a main body portion. The first stimulation arm is guided into and through a first intervertebral foramen. The first stimulation arm is positioned in proximity to a first dorsal root ganglion. The first stimulation aim is positioned with electrodes disposed along the first stimulation arm in operational proximity to the first dorsal root ganglion. The second stimulation arm is guided into and through a second intervertebral foramen. The second stimulation arm is positioned in proximity to a second dorsal root ganglion. The second stimulation arm is positioned with electrodes disposed along the second stimulation arm in operational proximity to the second dorsal root ganglion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims is a continuation of U.S. application Ser. No.13/901,158 filed May 23, 2013, now U.S. Pat. No. 8,718,790, which claimsthe benefit under 35 U.S.C. §119(e) of U.S. Provisional PatentApplication Ser. No. 61/651,917 filed on May 25, 2012, which isincorporated herein by reference.

FIELD

The present invention is directed to the area of implantable electricalstimulation systems and methods of making and using the systems. Thepresent invention is also directed to implantable electrical stimulationleads configured and arranged for simultaneously stimulating two or moredorsal root ganglia with a single lead, as well as methods of making andusing the leads and electrical stimulation systems.

BACKGROUND

Implantable electrical stimulation systems have proven therapeutic in avariety of diseases and disorders. For example, spinal cord stimulationsystems have been used as a therapeutic modality for the treatment ofchronic pain syndromes. Peripheral nerve stimulation has been used totreat incontinence, as well as a number of other applications underinvestigation. Functional electrical stimulation systems have beenapplied to restore some functionality to paralyzed extremities in spinalcord injury patients.

Stimulators have been developed to provide therapy for a variety oftreatments. A stimulator can include a control module (with a pulsegenerator), one or more leads, and an array of stimulator electrodes oneach lead. The stimulator electrodes are in contact with or near thenerves, muscles, or other tissue to be stimulated. The pulse generatorin the control module generates electrical pulses that are delivered bythe electrodes to body tissue.

Dorsal root ganglia are nodules of cell bodies disposed along the dorsalroots of spinal nerves. Dorsal root ganglia are disposed external to theepidural space. Dorsal root ganglia, however, are disposed in proximityto the spinal cord and the vertebral column.

BRIEF SUMMARY

In one embodiment, a method for implanting an electrical stimulationlead into a patient includes advancing a distal end of a multi-armedlead into an epidural space of the patient. The multi-armed leadincludes a main body portion, a first stimulation arm extending from adistal end of the main body portion, and a second stimulation armextending from the distal end of the main body portion. The firststimulation arm is guided into and through a first intervertebralforamen from inside the epidural space. The first stimulation arm ispositioned in proximity to a first dorsal root ganglion that extendsthrough the first intervertebral foramen. The first stimulation arm ispositioned with a plurality of electrodes disposed along the firststimulation arm in operational proximity to the first dorsal rootganglion. The second stimulation arm is guided into and through a secondintervertebral foramen from inside the epidural space. The secondstimulation arm is positioned in proximity to a second dorsal rootganglion that extends through the second intervertebral foramen. Thesecond stimulation arm is positioned with a plurality of electrodesdisposed along the second stimulation arm in operational proximity tothe second dorsal root ganglion.

In another embodiment, an implantable lead for providing electricalstimulation to a patient includes a lead body having a proximal end, adistal end, and a longitudinal length. The lead body includes a mainbody portion having a proximal end, a distal end, and a longitudinallength. A first stimulation arm extends from the distal end of the mainbody portion. The first stimulation arm has a radius of curvature. Aplurality of electrodes are disposed along the first stimulation arm. Asecond stimulation arm extends from the distal end of the main bodyportion. The second stimulation arm has a radius of curvature. Aplurality of electrodes are disposed along the second stimulation arm. Aplurality of terminals are disposed at the proximal end of the main bodyportion. A plurality of conductors electrically couple the plurality ofterminals to the plurality of electrodes. At least one of the pluralityof conductors electrically couples at least one terminal of theplurality of terminals to at least one electrode of the plurality ofelectrodes disposed along the first stimulation aim. At least one of theplurality of conductors electrically couples at least one terminal ofthe plurality of terminals to at least one electrode of the plurality ofelectrodes disposed along the second stimulation arm.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention aredescribed with reference to the following drawings. In the drawings,like reference numerals refer to like parts throughout the variousfigures unless otherwise specified.

For a better understanding of the present invention, reference will bemade to the following Detailed Description, which is to be read inassociation with the accompanying drawings, wherein:

FIG. 1 is a schematic view of another embodiment of an electricalstimulation system that includes a percutaneous lead body coupled to acontrol module, according to the invention;

FIG. 2A is a schematic view of one embodiment of a plurality ofconnector assemblies disposed in the control module of FIG. 1, theconnector assemblies configured and arranged to receive the proximalportions of the lead bodies of FIG. 1, according to the invention;

FIG. 2B is a schematic view of one embodiment of a proximal portion ofthe lead body of FIG. 1, a lead extension, and the control module ofFIG. 1, the lead extension configured and arranged to couple the leadbody to the control module, according to the invention;

FIG. 3A is a schematic transverse cross-sectional view of spinal nervesextending from a spinal cord, the spinal nerves including dorsal rootganglia;

FIG. 3B is a schematic perspective view of a portion of the spinal cordof FIG. 3A disposed in a portion of a vertebral column with the dorsalroot ganglia of FIG. 3A extending outward from the vertebral column;

FIG. 3C is a schematic top view of a portion of the spinal cord of FIG.3A disposed in a vertebral foramen defined in a vertebra of thevertebral column of FIG. 3B, the vertebra also defining intervertebralforamina extending between an outer surface of the vertebra and thevertebral foramen, the intervertebral foramina providing an openingthrough which the dorsal root ganglia of FIG. 3B can extend outward fromthe spinal cord of FIG. 3B;

FIG. 3D is a schematic side view of two vertebrae of the vertebralcolumn of FIG. 3B, the vertebrae defining an intervertebral foramenthrough which one of the dorsal root ganglia of FIG. 3B can extendoutward from the spinal cord of FIG. 3B;

FIG. 4 is a schematic side view of one embodiment of a distal end of amulti-armed lead, the multi-armed lead including a body with twostimulation arms extending from a distal end of a major portion of thebody; according to the invention;

FIG. 5A is a transverse cross-sectional view of one embodiment of aportion of the major portion of the body of FIG. 4, the major portionincluding a multi-lumen conductor guide that defines a stylet lumen anda plurality of conductor lumens arranged around the stylet lumen,according to the invention;

FIG. 5B is a transverse cross-sectional view of one embodiment ofconductors disposed in each of a plurality of conductor lumens of themulti-lumen conductor guide of FIG. 5A, according to the invention;

FIG. 6 is a transverse cross-sectional view of an alternate embodimentof a portion of the major portion of the body of FIG. 4, the majorportion including a multi-lumen conductor guide that defines two styletlumens and a plurality of conductor lumens arranged around the styletlumens, according to the invention;

FIG. 7A is a schematic transverse cross-sectional view of one embodimentof a portion of one of the stimulation arms of the body of FIG. 4, thestimulation arm including a multi-lumen conductor guide that defines astylet lumen and a plurality of conductor lumens arranged around thestylet lumen, according to the invention;

FIG. 7B is a schematic transverse cross-sectional view of one embodimentof a portion of one of the stimulation arms of the body of FIG. 4, thestimulation arm including a multi-lumen conductor guide that defines astylet lumen and a plurality of conductor lumens arranged around thestylet lumen, according to the invention;

FIG. 8 is a schematic perspective view of the spinal cord of FIG. 3Adisposed along a longitudinal transverse view of a portion of thevertebral column of FIG. 3B, where a side view of the distal end of themulti-armed lead of FIG. 4 is shown disposed along a portion of thespinal cord with electrodes of the multi-armed lead disposed along sideof dorsal root ganglia extending from the spinal cord, according to theinvention;

FIG. 9 is a schematic side view of the distal end of the multi-armedlead of FIG. 4, where stimulation arms of the multi-armed lead arecoupled to one another along a perforated line, according to theinvention; and

FIG. 10 is a schematic overview of one embodiment of components of anelectrical stimulation system, according to the invention.

DETAILED DESCRIPTION

The present invention is directed to the area of implantable electricalstimulation systems and methods of making and using the systems. Thepresent invention is also directed to implantable electrical stimulationleads configured and arranged for anchoring to one or more bonystructures in proximity to a target stimulation region, as well asmethods of making and using the leads and electrical stimulationsystems.

Suitable implantable electrical stimulation systems include, but are notlimited to, an electrode lead (“lead”) with one or more electrodesdisposed on a distal end of the lead and one or more terminals disposedon one or more proximal ends of the lead. Leads include, for example,deep brain stimulation leads, percutaneous leads, paddle leads, and cuffleads. Examples of electrical stimulation systems with leads are foundin, for example, U.S. Pat. Nos. 6,181,969; 6,516,227; 6,609,029;6,609,032; 6,741,892; 7,244,150; 7,672,734; 7,761,165; 7,949,395;7,974,706; 8,175,710; 8,224,450; and 8,364,278; and U.S. PatentApplication Publication No. 2007/0150036, all of which are incorporatedby reference.

FIG. 1 illustrates schematically one embodiment of an electricalstimulation system 100. The electrical stimulation system 100 includes acontrol module (e.g., a stimulator or pulse generator) 102 and apercutaneous lead 103. The lead 103 includes a plurality of electrodes134 that form an array of electrodes 133. The control module 102typically includes an electronic subassembly 110 and an optional powersource 120 disposed in a sealed housing 114. The lead 103 includes alead body 106 coupling the control module 102 to the plurality ofelectrodes 134. In at least some embodiments, the lead body 106 isisodiametric.

The control module 102 typically includes one or more connectorassemblies 144 into which the proximal end of the lead body 106 can beplugged to make an electrical connection via connector contacts (e.g.,216 in FIG. 2A) disposed in the connector assembly 144 and terminals(e.g., 210 in FIG. 2A) disposed along the lead body 106. The connectorcontacts are coupled to the electronic subassembly 110 and the terminalsare coupled to the electrodes 134. Optionally, the control module 102may include a plurality of connector assemblies 144.

The one or more connector assemblies 144 may be disposed in a header150. The header 150 provides a protective covering over the one or moreconnector assemblies 144. The header 150 may be formed using anysuitable process including, for example, casting, molding (includinginjection molding), and the like. In addition, one or more leadextensions 224 (see FIG. 2C) can be disposed between the lead body 106and the control module 102 to extend the distance between the lead body106 and the control module 102.

The electrical stimulation system or components of the electricalstimulation system, including the lead body 106 and the control module102, are typically implanted into the body of a patient. The electricalstimulation system can be used for a variety of applications including,but not limited to, spinal cord stimulation, brain stimulation, neuralstimulation, muscle activation via stimulation of nerves innervatingmuscle, and the like.

The electrodes 134 can be formed using any conductive, biocompatiblematerial. Examples of suitable materials include metals, alloys,conductive polymers, conductive carbon, and the like, as well ascombinations thereof. In at least some embodiments, one or more of theelectrodes 134 are formed from one or more of: platinum, platinumiridium, palladium, titanium, or rhenium.

The number of electrodes 134 in the array of electrodes 133 may vary.For example, there can be two, three, four, five, six, seven, eight,nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, or moreelectrodes 134. As will be recognized, other numbers of electrodes 134may also be used. In FIG. 1, sixteen electrodes 134 are shown. Theelectrodes 134 can be formed in any suitable shape including, forexample, round, oval, triangular, rectangular, pentagonal, hexagonal,heptagonal, octagonal, or the like.

The electrodes of the lead body 106 are typically disposed in, orseparated by, a non-conductive, biocompatible material including, forexample, silicone, polyurethane, and the like or combinations thereof.The lead body 106 may be formed in the desired shape by any processincluding, for example, molding (including injection molding), casting,and the like. Electrodes and connecting wires can be disposed onto orwithin a paddle body either prior to or subsequent to a molding orcasting process. The non-conductive material typically extends from thedistal end of the lead body 106 to the proximal end of the lead body106.

Terminals (e.g., 210 in FIG. 2A) are typically disposed at the proximalend of the lead body 106 for connection to corresponding conductivecontacts (e.g., 216 in FIG. 2A) in one or more connector assemblies(e.g., 144 in FIG. 1) disposed on, for example, the control module 102(or to other devices, such as conductive contacts on a lead extension,an operating room cable, a splitter, an adaptor, or the like).

Conductive wires (see e.g., 508 of FIG. 5B) extend from the plurality ofterminals (see e.g., 210 in FIG. 2A) to the plurality of electrodes 133.Typically, each of the plurality of terminals is electrically coupled toat least one of the plurality of electrodes 133. In some embodiments,each of the plurality of terminals is coupled to a single electrode 134of the plurality of electrodes 133.

The conductive wires may be embedded in the non-conductive material ofthe lead or can be disposed in one or more lumens (not shown) extendingalong the lead. In some embodiments, there is an individual lumen foreach conductive wire. In other embodiments, two or more conductive wiresmay extend through a lumen. There may also be one or more lumens (notshown) that open at, or near, the proximal end of the lead, for example,for inserting a stylet rod to facilitate placement of the lead within abody of a patient. Additionally, there may also be one or more lumens(not shown) that open at, or near, the distal end of the lead, forexample, for infusion of drugs or medication into the site ofimplantation of the lead 103. The one or more lumens may, optionally, beflushed continually, or on a regular basis, with saline, epidural fluid,or the like. The one or more lumens can be permanently or removablysealable at the distal end.

As discussed above, the lead body 106 may be coupled to the one or moreconnector assemblies 144 disposed on the control module 102. The controlmodule 102 can include any suitable number of connector assemblies 144including, for example, two three, four, five, six, seven, eight, ormore connector assemblies 144. It will be understood that other numbersof connector assemblies 144 may be used instead. In FIG. 1, the leadbody 106 includes eight terminals that are shown coupled with eightconductive contacts disposed in the connector assembly 144.

FIG. 2A is a schematic side view of one embodiment of a connectorassembly 144 disposed on the control module 102. In FIG. 2A, theproximal end 306 of the lead body 106 is shown configured and arrangedfor insertion to the control module 102.

In FIG. 2A, the connector assembly 144 is disposed in the header 150. Inat least some embodiments, the header 150 defines a port 204 into whichthe proximal end 206 of the lead body 106 with terminals 210 can beinserted, as shown by directional arrows 212, in order to gain access tothe connector contacts disposed in the connector assembly 144.

The connector assembly 144 includes a connector housing 214 and aplurality of connector contacts 216 disposed therein. Typically, theconnector housing 214 defines a port (not shown) that provides access tothe plurality of connector contacts 216. In at least some embodiments,the connector assembly 144 further includes a retaining element 218configured and arranged to fasten the corresponding lead body 106 to theconnector assembly 144 when the lead body 106 is inserted into theconnector assembly 144 to prevent undesired detachment of the lead body106 from the connector assembly 144. For example, the retaining element218 may include an aperture 220 through which a fastener (e.g., a setscrew, pin, or the like) may be inserted and secured against an insertedlead body 106.

When the lead body 106 is inserted into the port 204, the connectorcontacts 216 can be aligned with the terminals 210 disposed on the leadbody 106 to electrically couple the control module 102 to the electrodes(134 of FIG. 1) disposed at a distal end of the lead body 106. Examplesof connector assemblies in control modules are found in, for example,U.S. Pat. Nos. 7,244,150 and 8,224,450, which are incorporated byreference.

In at least some embodiments, the electrical stimulation system includesone or more lead extensions. The lead body 106 can be coupled to one ormore lead extensions which, in turn, are coupled to the control module102. In FIG. 2B, a lead extension connector assembly 222 is disposed ona lead extension 224. The lead extension connector assembly 222 is showndisposed at a distal end 226 of the lead extension 224. The leadextension connector assembly 222 includes a contact housing 228. Thecontact housing 228 defines at least one port 230 into which a proximalend 206 of the lead body 106 with terminals 210 can be inserted, asshown by directional arrow 238. The lead extension connector assembly222 also includes a plurality of connector contacts 240. When the leadbody 106 is inserted into the port 230, the connector contacts 240disposed in the contact housing 228 can be aligned with the terminals210 on the lead body 106 to electrically couple the lead extension 224to the electrodes (134 of FIG. 1) disposed at a distal end (not shown)of the lead body 106.

The proximal end of a lead extension can be similarly configured andarranged as a proximal end of a lead body. The lead extension 224 mayinclude a plurality of conductive wires (not shown) that electricallycouple the connector contacts 240 to terminal on a proximal end 248 ofthe lead extension 224. The conductive wires disposed in the leadextension 224 can be electrically coupled to a plurality of terminals(not shown) disposed on the proximal end 248 of the lead extension 224.In at least some embodiments, the proximal end 248 of the lead extension224 is configured and arranged for insertion into a lead extensionconnector assembly disposed in another lead extension. In otherembodiments (as shown in FIG. 2B), the proximal end 248 of the leadextension 224 is configured and arranged for insertion into theconnector assembly 144 disposed on the control module 102.

Turning to FIG. 3A, in at least some embodiments one or more dorsal rootganglia (“DRG”) are potential target stimulation locations. FIG. 3Aschematically illustrates a transverse cross-sectional view of a spinalcord 302 surrounded by dura 304. The spinal cord 302 includes a midline306 and a plurality of levels from which spinal nerves 312 a and 312 bextend. In at least some spinal cord levels, the spinal nerves 312 a and312 b extend bilaterally from the midline 306 of the spinal cord 302. InFIG. 3A, the spinal nerves 312 a and 312 b are shown attaching to thespinal cord 302 at a particular spinal cord level via correspondingdorsal roots 314 a and 314 b and corresponding ventral (or anterior)roots 316 a and 316 b. Typically, the dorsal roots 314 a and 314 b relaysensory information into the spinal cord 302 and the ventral roots 316 aand 316 b relay motor information outward from the spinal cord 302. TheDRG 320 a and 320 b are nodules of cell bodies that are disposed alongthe dorsal roots 316 a and 316 b in proximity to the spinal cord 302.

FIG. 3B schematically illustrates a perspective view of a portion of thespinal cord 302 disposed along a portion of a vertebral column 330. Thevertebral column 330 includes stacked vertebrae, such as vertebrae 332 aand 332 b, and a plurality of DRGs 320 a and 320 b extending outwardlybilaterally from the spinal cord 302 at different spinal cord levels.

FIG. 3C schematically illustrates a top view of a portion of the spinalcord 302 and surrounding dura 304 disposed in a vertebral foramen 340defined in the vertebra 332 b. The vertebrae, such as the vertebrae 332a and 332 b, are stacked together and the vertebral foramina 340 of thevertebrae collectively form a spinal canal through which the spinal cord302 extends. The space within the spinal canal between the dura 304 andthe walls of the vertebral foramen 340 defines the epidural space 342.Intervertebral foramina 346 a and 346 b, defined bilaterally along sidesof the vertebra 332 b, form openings through the vertebra 332 b betweenthe epidural space 342 and the environment external to the vertebra 332b.

FIG. 3D schematically illustrates a side view of two vertebrae 332 a and332 b coupled to one another by a disc 344. In FIG. 3D, theintervertebral foramen 346 b is shown defined between the vertebrae 332a and 332 b. The intervertebral foramen 346 b provides an opening forone or more of the dorsal root 314 b, ventral root 316 b, and DRG 320 bto extend outwardly from the spinal cord 302 to the environment externalto the vertebrae 332 a and 332 b.

Turning to FIG. 4, although the DRG are not within the epidural space,the DRG may be accessible to a lead from within the epidural space viathe intervertebral foramina. In at least some embodiments, once thedistal end of the lead is inserted into the epidural space the distalend of the lead can be advanced out of the epidural space through one ofthe intervertebral foramen, and positioned in proximity to the desiredDRG.

In at least some instances, it is desirable to concurrently stimulatetwo or more DRG, such as both DRG located at a particular spinal cordlevel (e.g., the DRG 320 a and 320 b), or two or more DRG located on thesame side of a vertebral column, or even two or more DRG at differentspinal cord levels and on different sides of the vertebral column. Inwhich case, separate conventional leads may be used to independentlystimulate each DRG. Introducing two or more leads into the epiduralspace may require that each of the leads be separately introduced intothe patient, thereby potentially increasing the time and complexity ofan implantation procedure, and also potentially requiring the patient toundergo several different needle insertions. Introducing two or moreleads into the epidural space may also be hindered due to sizeconstraints within the epidural space.

As herein described, a multi-armed percutaneous lead includes aplurality of electrodes disposed on each of multiple distal arms. Themulti-armed lead may be used to simultaneously stimulate two or moretarget stimulation regions, such as two or more different DRG, using asingle lead. In at least some embodiments, the multi-armed lead may beused to perform simultaneous stimulation of each of two bilateral DRG(e.g., at a desired spinal level) using a single lead.

FIG. 4 is a schematic side view of one embodiment of a distal end of amulti-armed lead 402. The multi-armed lead 402 includes a body 404 witha major portion 406 and a plurality of stimulation arms 408 a and 408 bextending from the major portion 406. In FIG. 4, the plurality ofstimulation arms 408 a and 408 b are shown extending from a distal endof the major portion 406. The multi-armed lead 402 can include anysuitable number of stimulation mins 408 a and 408 b extending from themajor portion 406. In FIG. 4, two stimulation arms 408 a and 408 b areshown. It will be understood that other numbers of stimulation arms 408a and 408 b may be extended from the major portion 406 including, forexample, three, four, five, six, seven, eight, or more stimulation arms408 a and 408 b.

One or more electrodes, such as electrodes 416 a and 416 b, are disposedon each of the stimulation arms 408 a and 408 b, respectively. In FIG.4, four electrodes are disposed on each of the stimulation arms 408 aand 408 b. It will be understood that any suitable number of electrodesmay be disposed on each of the stimulation arms 408 a and 408 bincluding, for example, one, two, three, four, five, six, seven, eight,nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, or moreelectrodes. In some embodiments, the same number of electrodes isdisposed on each of the stimulation arms 408 a and 408 b. In otherembodiments, a different number of electrodes are disposed on each ofthe stimulation arms 408 a and 408 b.

In at least some embodiments, the electrodes are configured as ringelectrodes that extend completely around radii of curvature of thestimulation arms 408 a and 408 b. In at least some other embodiments,the electrodes are configured such that the electrodes extend aroundless than complete radii of curvature of the stimulation arms 408 a and408 b. For example, the electrodes may be formed as segmentedelectrodes, cuff-shaped electrodes, arc-shaped electrodes, a tipelectrode, or the like. It may be an advantage to form the electrodessuch that, for each of the stimulation arms 408 a and 408 b, theelectrodes extend around less than a complete radius of curvature of thestimulation arm so that energy propagated from the electrodes can bedirected primarily in the direction of the target stimulation location.

A plurality of terminals (see e.g., terminals 210 of FIGS. 2A-2B) aredisposed at a proximal end of the lead body 404. In at least someembodiments, the number of terminals is equal to the collective numberof electrodes disposed on each of the stimulation arms 408 a and 408 b.A plurality of elongated conductors (508 in FIG. 5B) electricallycouples the terminals to the electrodes.

In at least some embodiments, the stimulation arms 408 a and 408 b eachinclude at least one bend 420 a and 420 b, respectively. In at leastsome embodiments, the stimulation arms 408 a and 408 b each includeexactly one bend 420 a and 420 b, respectively. In at least someembodiments, the at least one bends 420 a and 420 b are configured andarranged to extend their respective stimulation arms 408 a and 408 b inopposite directions from one another. In at least some embodiments, theat least one bend 420 a and the at least one bend 420 b are symmetricalwith one another along an axis extending along a longitudinal length ofa distal end of the major portion 406 of the lead body 404.

In at least some embodiments, the at least one bend 420 a and the atleast one bend 420 b are pre-defined in their respective stimulationarms (e.g., the bends 420 a and 420 b are formed during manufacture orprior to distribution to practitioners). In at least some embodiments,the at least one bend 420 a and the at least one bend 420 b arepre-defined such that the bends 420 a and 420 b are configured andarranged for insertion into bilateral intervertebral foramina frominside the epidural space. In at least some alternate embodiments, theat least one bend 420 a and the at least one bend 420 b are formable bypractitioners prior to, or during, an implantation procedure.

In at least some embodiments, the at least one bend 420 a and the atleast one bend 420 b are each no less than 50°, 60°, 70°, 80°, 90°,100°, 110°, 120°, 130°, 140°, 150°, 160°, or more. In at least someembodiments, the at least one bend 420 a and the at least one bend 420 bare each no greater than 160°, 150°, 140°, 130°, 120°, 110°, 100°, 90°,80°, 70°, 60°, 50°, or less. In at least some embodiments, the at leastone bend 420 a and the at least one bend 420 b are each no less than 60°and no greater than 150°. In at least some embodiments, the at least onebend 420 a and the at least one bend 420 b are each no less than 80° andno greater than 130°.

In at least some embodiments, the at least one bend 420 a and the atleast one bend 420 b are each configured and arranged to be straightenedout upon application of force, yet also configured and arranged toreform upon removal of the force. For example, the at least one bend 420a and the at least one bend 420 b may be configured and arranged to bestraightened out when a stylet is inserted along one or more lumensdefined within the stimulation arms 408 a and 408 b, or when thestimulation arms 408 a and 408 b are disposed in an introducer orinsertion needle, or the like. In at least some embodiments, thecurvature of the at least one bend 420 a and the at least one bend 420 bare each formed from one or more pre-shaped components of thestimulation arms 408 a and 408 b including, for example, pre-shapedinsulation, or pre-shaped conductors, or both.

Turning to FIG. 5A, in at least some embodiments the major portion ofthe lead body includes a multi-lumen conductor guide. FIG. 5A is atransverse cross-sectional view of one embodiment of the major portion406 of the lead body 404. In at least some embodiments, the majorportion 406 of the lead body 404 includes an elongated multi-lumenconductor guide 502 defining a single stylet lumen 504 and a pluralityof conductor lumens, such as conductor lumen 506, disposed around thestylet lumen 504. The stylet lumen 504 may be configured and arranged toreceive a stylet for stiffening the multi-armed lead and assisting ininsertion and positioning of the multi-armed lead in the patient. Themulti-lumen conductor guide 502 can define any suitable number ofconductor lumens 506 for receiving any suitable number of conductors. Inat least some embodiments, the multi-lumen conductor guide 502 defineseight conductor lumens 506. In at least some embodiments, themulti-lumen conductor guide 502 defines sixteen conductor lumens 506.

FIG. 5B is a transverse cross-sectional view of one embodiment ofconductors, such as conductor 508, disposed in conductor lumens 506. Inat least some embodiments, insulation 510 is disposed around theconductors 508 to prevent short-circuiting of the conductors 508. Themulti-lumen conductor guide 502 may extend an entire longitudinal lengthof the major portion 406 of the lead body 106. The conductors 508 can beformed from any conductor suitable for implantation. The conductorlumens 506 can be configured and arranged to each receive a singleconductor 508 or a plurality of conductors 508. In embodiments thatinclude conductors formed from conductive wires, it will be understoodthat an individual conductor 508 can be formed from conductive wiresthat are either single-filar or multi-filar.

Turning to FIG. 6, in at least some embodiments the multi-lumenconductor guide defines a plurality of stylet lumens. FIG. 6 is atransverse cross-sectional view of another embodiment of a portion ofthe major portion 406. In at least some embodiments, the multi-lumenconductor guide 502 defines a plurality of stylet lumens 504 a and 504b. In at least some embodiments, the number of stylet lumens 504 isequal to the number of stimulation arms 408 a and 408 b. In FIG. 6, themulti-lumen conductor guide 502 defines two stylet lumens 504 a and 504b. As discussed below, it may be advantageous for the multi-lumenconductive guide 502 to define a plurality of stylet lumens 504 toenable a plurality of stylets to be simultaneously used to independentlyguide each of the stimulation arms 408 a and 408 b.

Turning to FIG. 7A, in at least some embodiments the stimulation armsinclude multi-lumen conductor guides. FIG. 7A is a transversecross-sectional view of one embodiment of a portion of the stimulationarm 408 a. The stimulation arm 408 a includes a multi-lumen conductorguide 702 a that defines a stylet lumen 704 a and a plurality ofconductor lumens, such as conductor lumen 706 a, arranged around thestylet lumen 704 a. The multi-lumen conductor guide 702 a can define anysuitable number of conductor lumens 706 a. In at least some embodiments,the multi-lumen conductor guide 702 a defines four conductor lumens 706a. In at least some embodiments, the multi-lumen conductor guide 702 adefines eight conductor lumens 706 a. In at least some embodiments, themulti-lumen conductor guide 702 a defines half the number of conductorlumens 706 a as does the multi-lumen conductor guide 502 a.

FIG. 7B is a transverse cross-sectional view of one embodiment of aportion of the stimulation arm 408 b. The stimulation arm 408 b includesa multi-lumen conductor guide 702 b that defines a stylet lumen 704 band a plurality of conductor lumens, such as conductor lumen 706 barranged around the stylet lumen 704 b. The multi-lumen conductor guide702 b can define any suitable number of conductor lumens 706 b. In atleast some embodiments, the multi-lumen conductor guide 702 b definesfour conductor lumens 706 b. In at least some embodiments, themulti-lumen conductor guide 702 b defines eight conductor lumens 706 b.In at least some embodiments, the multi-lumen conductor guide 702 bdefines half the number of conductor lumens 706 b as does themulti-lumen conductor guide 502 b. In at least some embodiments, themulti-lumen conductor guide 702 b defines the same number of conductorlumens as does the multi-lumen conductor guide 502 a.

Turning to FIG. 8, once the multi-armed lead is inserted into theepidural space, the multi-armed lead may be advanced to the spinal levelwhere bilateral DRG stimulation is desired and the stimulation arms 408a and 408 b can be extended through the intervertebral foramen at thatparticular spinal level and positioned such that electrodes disposedalong the stimulation arms are placed in operational proximity to theDRG.

FIG. 8 is a schematic perspective view of the spinal cord 302 disposedalong a schematic longitudinal cross-sectional view of a portion of thevertebral column 330. The portion of the vertebral column 330 shown inFIG. 8 includes the vertebrae 332 a and 332 b and intervertebralforamina 346 a and 346 b defined between the vertebrae 332 a and 332 bon opposing sides of the vertebral column 330. The DRG 320 a extendsoutward from the spinal cord 302 and through the intervertebral foramen346 a, and the DRG 320 b extends outward from the spinal cord 302 andthrough the intervertebral foramen 346 b. The DRG 320 c and 320 c arealso shown in FIG. 8 extending from other intervertebral foramina.

The multi-armed lead 402 is shown disposed in the epidural space 342along a portion of the midline 306 of the spinal cord 302. Thestimulation arms 408 a and 408 b of the multi-armed lead 402 areextended out of the epidural space 342 between the vertebrae 332 a and332 b. The stimulation arms 408 a and 408 b of the multi-armed lead 402are extended out of the epidural space 342 via the intervertebralforamina 346 a and 346 b such that the stimulation arm 408 a extendsthrough the intervertebral foramen 346 a and the stimulation arm 408 bextends through the intervertebral foramen 346 b.

The stimulation arm 408 a is extended through the intervertebral foramen346 a such that the electrodes 416 a disposed along the stimulation arm408 a are positioned in operational proximity to the DRG 320 a.Similarly, the stimulation arm 408 b is extended through theintervertebral foramen 346 b such that the electrodes 416 b disposedalong the stimulation arm 408 b are positioned in operational proximityto the DRG 320 b.

Providing the multi-armed lead 402 with two stimulation arms 408 a and408 b enables a single lead to simultaneously extend through the twointervertebral foramina 346 a and 346 b. In at least some embodiments,the stimulation arms 408 a and 408 b are configured and arranged toposition the electrodes 416 a and 416 b such that the electrodes 416 aand 416 b are disposed in operational proximity to the DRG 320 a and 320b, respectively, such that the electrodes 416 a and 416 b cansimultaneously stimulate the two DRG 320 a and 320 b, if desired. In atleast some embodiments, the bends 420 a and 420 b also function toanchor the multi-armed lead 402 to the vertebral column 330 and toprevent the electrodes 416 a and 416 b from migrating away from the DRG320 a and 320 b, respectively, over time.

It will be understood that, alternately, the stimulation arms 408 a and408 b can be implanted to concurrently stimulate two or more DRG locatedon the same side of a vertebral column (e.g., the DRG 320 a and 320 c,or 320 b and 320 d), or even two or more DRG at different spinal cordlevels and on different sides of the vertebral column (e.g., the DRG 320a and 320 d, or 320 b and 320 c).

It will also be understood that FIG. 8 is a schematic representation ofthe multi-armed lead 402 disposed in and around the vertebral column330. The shapes and dimensions of the anatomical structures and at leastsome of the components of the multi-armed lead 402 are not be drawn toscale in FIG. 8, for clarity of illustration.

The multi-armed lead 402 can be implanted in any suitable manner.Several exemplary techniques are provided herein. In at least someembodiments, the multi-armed lead is advanced into the epidural spacevia a needle, such as an epidural needle. In at least some embodiments,the needle includes an obturator. Once the needle is advanced into theepidural space, the multi-armed lead is inserted into the needle and thedistal end of the multi-armed lead is advanced to the epidural space.Once in the epidural space, the stimulation arms of the multi-armed leadare each guided within the epidural space and positioned in proximity toa different target stimulation location either in the epidural space orin proximity to the epidural space, such as two different DRG.

In at least some embodiments, one or more stylets are used to providestiffness to the multi-armed lead to facilitate advancement of themulti-armed lead (e.g., along the needle, or within the epidural space,or both). For example, the one or more stylets can be inserted into theone or more stylet lumens of the multi-armed lead and used to guide thestimulation arms 408 a and 408 b of the multi-armed lead within theepidural space into and through the desired intervertebral foramina,such as the intervertebral foramina 346 a and 346 b, and in operationalproximity to the target stimulation location (e.g., the DRG).

In at least some embodiments, when the distal end of the multi-armedlead is guided within the epidural space into and through the desiredintervertebral foramina by a single stylet, the single stylet isdisposed in the stylet lumen 504 of the major portion 406 of the leadbody 404 (see e.g., FIG. 5A) and extended along the stylet lumen 504 andinto the stylet lumen 704 a of the stimulation arm 408 a (see e.g., FIG.7A). The stylet can then be used to guide that stimulation arm 408 ainto (and through) the intervertebral foramina 346 a. Once theelectrodes 416 a of the stimulation arm 408 a are in operationalproximity to the target stimulation location (e.g., the DRG 320 a), thestylet can be removed from the stylet lumen 704 a and inserted into thestylet lumen 704 b of the stimulation arm 408 b (see e.g., FIG. 7B). Thestylet can then be used to guide the stimulation arm 408 b into (andthrough) the intervertebral foramina 346 b and position the electrodes416 b in operational proximity to the target stimulation location (e.g.,the DRG 320 b).

In at least some other embodiments, when the distal end of themulti-armed lead is guided within the epidural space into and throughthe desired intervertebral foramina by two stylets, the two stylets aresimultaneously disposed in the stylet lumen 504 of the major portion 406of the lead body 404 (see e.g., FIG. 5A) with one of the two styletsextending into the stylet lumen 704 a of the stimulation arm 408 a (seee.g., FIG. 7A), and the other of the two stylets extending into thestylet lumen 704 b of the stimulation arm 408 b (see e.g., FIG. 7B).

Alternately, in at least some other embodiments when the distal end ofthe multi-armed lead is guided within the epidural space into andthrough the desired intervertebral foramina by two stylets, one of thetwo stylets is disposed in the stylet lumen 504 a (see e.g., FIG. 6) ofthe major portion 406 of the lead body 404 and extended into the styletlumen 704 a of the stimulation arm 408 a (see e.g., FIG. 7A), and theother of the two stylets is disposed in the stylet lumen 504 b (seee.g., FIG. 6) of the major portion 406 of the lead body 404 and extendedinto the stylet lumen 704 b of the stimulation arm 408 b (see e.g., FIG.7B).

It may be advantageous to use two stylets so that the two stimulationarms 408 a and 408 b may be simultaneously implanted, or sequentiallyimplanted without needing to move a stylet between the stylet lumens 704a and 704 b. Optionally, the one or more stylets can be steerable tofacilitate guidance of the stimulation arms 408 a and 408 b into (andthrough) the desired intervertebral foramina, and in operationalproximity to the target stimulation location (e.g., the DRG).

In at least some embodiments, the multi-armed lead is implanted into thepatient using a combination of the needle and an introducer. Forexample, the needle may be advanced into the epidural space, asdiscussed above. Once the needle is in the epidural space, the obturatoris removed and a guidewire is inserted into the needle and advanced intothe epidural space. The needle is removed leaving the guidewire disposedin the epidural space.

A flexible introducer is disposed over the guidewire and advanced intothe epidural space. The multi-armed lead is inserted into the introducerand advanced to the epidural space. When the stimulation arms aredisposed in the introducer, the walls of the introducer exert a forceagainst the stimulation arms that straighten the stimulation arms enoughto be contained within the introducer.

In at least some embodiments, the introducer is disposed in the epiduralspace such that when the distal end of the multi-armed lead is extendedoutward from a distal end of the introducer, the stimulation arms aredisposed along a region of the epidural space that is slightly beyondthe spinal level of the intervertebral foramina through which thestimulation arms of the lead are desired to extend to reach the targetstimulation location. When the stimulation arms are extended from thedistal end of the introducer, the stimulation arms bend to reform thebends (420 in FIG. 4). In at least some embodiments, the outer walls ofthe epidural space exert a force against the stimulation arms thatenable the stimulation arms to partially bend, but prevent thestimulation from fully bending. The introducer and multi-armed lead(with the partially-bent stimulation arms) are collectively pulled backand rotated (if needed) to position the distal tips of the stimulationarms into the desired intervertebral foramina.

The stimulation arms are then advanced through the intervertebralforamina to the target stimulation locations (e.g., the DRG). In atleast some embodiments, one or more stylets may be used to facilitateadvancement of the stimulation arms through the introducer, or throughthe intervertebral foramina, or both.

In at least some embodiments, the stimulation arms may be coupled to oneanother (e.g., via one or more perforations) while being advanced intothe epidural space. FIG. 9 is a schematic side view of the distal end ofthe multi-armed lead 402. The stimulation arms 408 a and 408 b arecoupled to one another. In FIG. 9, the stimulation arms 408 a and 408 bare coupled to one another via a perforated line 902. It will beunderstood that the stimulation arms 408 a and 408 b can be coupled toone another in any suitable manner including, for example, adhesive,sutures, or the like or combinations thereof.

When the stimulation arms 408 a and 408 b are coupled together, movementof one of the stimulation arms 408 a and 408 b causes a correspondingmovement of the other of the stimulation arms 408 a and 408 b. In atleast some embodiments, when the stimulation arms 408 a and 408 b arecoupled together the stimulation arms 408 a and 408 b do not bendindependently from one another. In at least some embodiments, when thestimulation arms 408 a and 408 b are coupled together the portion of thelead body 404 that includes the major portion 406 is isodiametric withthe portion of the lead body 404 that includes the stimulation arms 408a and 408 b along at least one transverse axis.

When the stimulation arms are coupled to one another, the multi-armedlead can be advanced into the epidural space via either the needle orthe introducer in combination with a guidewire. In at least someembodiments that include use of the guidewire, the guidewire is advancedinto the epidural space and through one of the desired intervertebralforamina to one of the target stimulation locations (e.g., one of theDRG). The multi-armed lead is then advanced over the guidewire into theepidural space and out through a first intervertebral foramen to a firsttarget stimulation location. A stylet is inserted into the multi-armedlead and used to uncouple the stimulation arms and reposition one of thestimulation arms out of the first intervertebral foramen and through asecond intervertebral foramen to a second target stimulation location.

For example, in at least some embodiments the multi-armed lead 402 isadvanced over the guidewire into the epidural space 342 and out throughthe intervertebral foramen 346 a until the electrodes 416 a of thestimulation arm 408 a are positioned in operational proximity to the DRG320 a. A stylet is inserted into the stylet lumen (504 or 504 b) of themajor portion 406 of the multi-armed lead 402 and into the stylet lumen704 b of the stimulation arm 408 b. The stylet is then used to uncouple(e.g., peel apart) the stimulation arms 408 a and 408 b such that theelectrodes 416 a of the stimulation arm 408 a remain in operationalproximity to the DRG 320 a. The stylet is used to reposition thestimulation arm 408 b out of the first intervertebral foramen 346 a,back into the epidural space 342, and out through the intervertebralforamen 346 b until the electrodes 416 b of the stimulation arm 408 bare positioned in operational proximity to the DRG 320 b.

FIG. 10 is a schematic overview of one embodiment of components of anelectrical stimulation system 1000 including an electronic subassembly1010 disposed within a control module. It will be understood that theelectrical stimulation system can include more, fewer, or differentcomponents and can have a variety of different configurations includingthose configurations disclosed in the stimulator references citedherein.

Some of the components (for example, power source 1012, antenna 1018,receiver 1002, and processor 1004) of the electrical stimulation systemcan be positioned on one or more circuit boards or similar carrierswithin a sealed housing of an implantable pulse generator, if desired.Any power source 1012 can be used including, for example, a battery suchas a primary battery or a rechargeable battery. Examples of other powersources include super capacitors, nuclear or atomic batteries,mechanical resonators, infrared collectors, thermally-powered energysources, flexural powered energy sources, bioenergy power sources, fuelcells, bioelectric cells, osmotic pressure pumps, and the like includingthe power sources described in U.S. Pat. No. 7,437,193, incorporatedherein by reference.

As another alternative, power can be supplied by an external powersource through inductive coupling via the optional antenna 1018 or asecondary antenna. The external power source can be in a device that ismounted on the skin of the user or in a unit that is provided near theuser on a permanent or periodic basis.

If the power source 1012 is a rechargeable battery, the battery may berecharged using the optional antenna 1018, if desired. Power can beprovided to the battery for recharging by inductively coupling thebattery through the antenna to a recharging unit 1016 external to theuser. Examples of such arrangements can be found in the referencesidentified above.

In one embodiment, electrical current is emitted by the electrodes 134on the paddle or lead body to stimulate nerve fibers, muscle fibers, orother body tissues near the electrical stimulation system. A processor1004 is generally included to control the timing and electricalcharacteristics of the electrical stimulation system. For example, theprocessor 1004 can, if desired, control one or more of the timing,frequency, strength, duration, and waveform of the pulses. In addition,the processor 1004 can select which electrodes can be used to providestimulation, if desired. In some embodiments, the processor 1004 mayselect which electrode(s) are cathodes and which electrode(s) areanodes. In some embodiments, the processor 1004 may be used to identifywhich electrodes provide the most useful stimulation of the desiredtissue.

Any processor can be used and can be as simple as an electronic devicethat, for example, produces pulses at a regular interval or theprocessor can be capable of receiving and interpreting instructions froman external programming unit 1008 that, for example, allows modificationof pulse characteristics. In the illustrated embodiment, the processor1004 is coupled to a receiver 1002 which, in turn, is coupled to theoptional antenna 1018. This allows the processor 1004 to receiveinstructions from an external source to, for example, direct the pulsecharacteristics and the selection of electrodes, if desired.

In one embodiment, the antenna 1018 is capable of receiving signals(e.g., RF signals) from an external telemetry unit 1006 which isprogrammed by a programming unit 1008. The programming unit 1008 can beexternal to, or part of, the telemetry unit 1006. The telemetry unit1006 can be a device that is worn on the skin of the user or can becarried by the user and can have a form similar to a pager, cellularphone, or remote control, if desired. As another alternative, thetelemetry unit 1006 may not be worn or carried by the user but may onlybe available at a home station or at a clinician's office. Theprogramming unit 1008 can be any unit that can provide information tothe telemetry unit 1006 for transmission to the electrical stimulationsystem 1000. The programming unit 1008 can be part of the telemetry unit1006 or can provide signals or information to the telemetry unit 1006via a wireless or wired connection. One example of a suitableprogramming unit is a computer operated by the user or clinician to sendsignals to the telemetry unit 1006.

The signals sent to the processor 1004 via the antenna 1018 and receiver1002 can be used to modify or otherwise direct the operation of theelectrical stimulation system. For example, the signals may be used tomodify the pulses of the electrical stimulation system such as modifyingone or more of pulse duration, pulse frequency, pulse waveform, andpulse strength. The signals may also direct the electrical stimulationsystem 1000 to cease operation, to start operation, to start chargingthe battery, or to stop charging the battery. In other embodiments, thestimulation system does not include an antenna 1018 or receiver 1002 andthe processor 1004 operates as programmed.

Optionally, the electrical stimulation system 1000 may include atransmitter (not shown) coupled to the processor 1004 and the antenna1018 for transmitting signals back to the telemetry unit 1006 or anotherunit capable of receiving the signals. For example, the electricalstimulation system 1000 may transmit signals indicating whether theelectrical stimulation system 1000 is operating properly or not orindicating when the battery needs to be charged or the level of chargeremaining in the battery. The processor 1004 may also be capable oftransmitting information about the pulse characteristics so that a useror clinician can determine or verify the characteristics.

The above specification, examples and data provide a description of themanufacture and use of the composition of the invention. Since manyembodiments of the invention can be made without departing from thespirit and scope of the invention, the invention also resides in theclaims hereinafter appended.

What is claimed as new and desired to be protected by Letters Patent ofthe United States is:
 1. A method for implanting an electricalstimulation lead into a patient, the method comprising: advancing adistal end portion of a multi-armed lead into an epidural space of thepatient, the multi-armed lead comprising a main body portion, a firststimulation arm extending from a distal end portion of the main bodyportion, and a second stimulation arm extending from the distal endportion of the main body portion; advancing the first stimulation armthrough a first intervertebral foramen from inside the epidural space;and advancing the second stimulation arm through a second intervertebralforamen from inside the epidural space.
 2. The method of claim 1,wherein the first intervertebral foramen and the second intervertebralforamen are disposed at a same spinal cord level.
 3. The method of claim1, wherein the first intervertebral foramen and the secondintervertebral foramen are disposed at different spinal cord levels. 4.The method of claim 1, wherein the first intervertebral foramen and thesecond intervertebral foramen are disposed along opposing sides of thepatient's vertebral column.
 5. The method of claim 1, wherein the firstintervertebral foramen and the second intervertebral foramen aredisposed along the same side of the patient's vertebral column.
 6. Themethod of claim 1, wherein guiding the first stimulation arm into andthrough the first intervertebral foramen from inside the epidural spacecomprises inserting a first stylet into the first stimulation arm andusing the first stylet to guide the first stimulation arm into andthrough the first intervertebral foramen.
 7. The method of claim 6,wherein guiding the second stimulation arm into and through the secondintervertebral foramen from inside the epidural space comprisesinserting the first stylet into the second stimulation arm and using thefirst stylet to guide the second stimulation arm into and through thesecond intervertebral foramen.
 8. The method of claim 6, wherein guidingthe second stimulation arm into and through the second intervertebralforamen from inside the epidural space comprises inserting a secondstylet into the second stimulation arm and using the second stylet toguide the second stimulation arm into and through the secondintervertebral foramen.
 9. The method of claim 8, wherein the firststylet and the second stylet are simultaneously disposed in themulti-armed lead during at least a portion of the implantation of themulti-armed lead into the patient.
 10. The method of claim 1, whereinadvancing a distal end portion of a multi-armed lead into an epiduralspace of the patient comprises advancing the distal end portion of themulti-armed lead into the epidural space of the patient while the firststimulation arm is coupled to the second stimulation arm.
 11. The methodof claim 10, further comprising uncoupling the second stimulation armfrom the first stimulation arm subsequent to advancing the distal endportion of the multi-armed lead into the epidural space of the patient.12. The method of claim 1, further comprising anchoring the firststimulation arm to the first intervertebral foramen using a pre-definedbend formed along the first stimulation arm; and anchoring the secondstimulation arm to the second intervertebral foramen using a pre-definedbend formed along the second stimulation arm.
 13. An implantable leadfor providing electrical stimulation to a patient, the lead comprising:a lead body having a proximal end portion, a distal end portion, and alongitudinal length, the lead body comprising a main body portion havinga proximal end portion, a distal end portion, and a longitudinal length,a first stimulation arm extending from the distal end portion of themain body portion, a plurality of first electrodes disposed along thefirst stimulation arm, a second stimulation arm extending from thedistal end portion of the main body portion, and a plurality of secondelectrodes disposed along the second stimulation arm, wherein the firststimulation arm is configured and arranged for extending through a firstintervertebral foramen when the main body portion is disposed in theepidural space, wherein the second stimulation arm is configured andarranged for extending through a second intervertebral foramen when themain body portion is disposed in an epidural space; a plurality ofterminals disposed along the proximal end portion of the main bodyportion; and a plurality of conductors electrically coupling theplurality of terminals to the plurality of first electrodes and to theplurality of second electrodes.
 14. The lead of claim 13, wherein afirst pre-defined bend is formed along the first stimulation arm and asecond pre-defined bend is formed along the second stimulation arm. 15.The lead of claim 14, wherein the first pre-defined bend is oriented inan opposite direction from the second pre-defined bend.
 16. The lead ofclaim 14, wherein the first pre-defined bend is symmetric with thesecond pre-defined bend along an axis of symmetry extending along thelongitudinal length of the major body portion.
 17. The lead of claim 14,wherein the first pre-defined bend and the second pre-defined bend areeach configured and arranged to straighten upon application of force andto reform upon removal of the applied force.
 18. The lead of claim 14,wherein the first pre-defined bend and the second pre-defined bend areeach no less than 50° and no greater than 160°.
 19. The lead of claim13, wherein the first stimulation arm and the second stimulation arm areconfigured and arranged for being removably coupled to one anotherduring insertion of the lead into the patient.
 20. An electricalstimulating system comprising: the lead of claim 13; a control moduleelectrically coupled to the plurality of first electrodes of the firststimulation arm of the lead and to the plurality of second electrodes ofthe second stimulation arm of the lead, the control module comprising ahousing, and an electronic subassembly disposed in the housing; and aconnector assembly for receiving the lead, the connector assemblycomprising a connector housing defining at least one port configured andarranged for receiving the major body portion of the lead, and aplurality of connector contacts disposed in the connector housing, theplurality of connector contacts configured and arranged to couple to theplurality of terminals disposed along the major body portion when themajor body portion is received by the at least one port.